Merge pull request #1349 from nats-io/token-supplier-from-property

Options allow token supplier from property, not just api method

Author: scottf

src/main/java/io/nats/client/Options.java

@@ -379,6 +379,10 @@ public class Options {
      * Property used to configure a builder from a Properties object. {@value}, see {@link Builder#token(String) token}.
      */
     public static final String PROP_TOKEN = PFX + "token";
+    /**
+     * Property used to configure the token supplier from a Properties object. {@value}, see {@link Builder#tokenSupplier(Supplier) tokenSupplier}.
+     */
+    public static final String PROP_TOKEN_SUPPLIER = PFX + "token.supplier";
     /**
      * Property used to configure a builder from a Properties object. {@value}, see {@link Builder#server(String) server}.
      */
@@ -882,6 +886,8 @@ public Builder properties(Properties props) {
             charArrayProperty(props, PROP_USERNAME, ca -> this.username = ca);
             charArrayProperty(props, PROP_PASSWORD, ca -> this.password = ca);
             charArrayProperty(props, PROP_TOKEN, ca -> this.tokenSupplier = new DefaultTokenSupplier(ca));
+            //noinspection unchecked
+            classnameProperty(props, PROP_TOKEN_SUPPLIER, o -> this.tokenSupplier = (Supplier<char[]>) o);
 
             booleanProperty(props, PROP_SECURE, b -> this.useDefaultTls = b);
             booleanProperty(props, PROP_OPENTLS, b -> this.useTrustAllTls = b);

src/test/java/io/nats/client/OptionsTests.java

@@ -892,6 +892,16 @@ public void testTokenSupplier() {
 
         connectString = o.buildProtocolConnectOptionsString(serverURI, true, null).toString();
         assertTrue(connectString.contains("\"auth_token\":\"short-lived-token-2\""));
+
+        Properties properties = new Properties();
+        properties.setProperty(PROP_TOKEN_SUPPLIER, TestingDynamicTokenSupplier.class.getCanonicalName());
+        o = new Options.Builder().properties(properties).build();
+
+        connectString = o.buildProtocolConnectOptionsString(serverURI, true, null).toString();
+        assertTrue(connectString.contains("\"auth_token\":\"dynamic-token-1\""));
+
+        connectString = o.buildProtocolConnectOptionsString(serverURI, true, null).toString();
+        assertTrue(connectString.contains("\"auth_token\":\"dynamic-token-2\""));
     }
 
     @Test

src/test/java/io/nats/client/TestingDynamicTokenSupplier.java

@@ -0,0 +1,26 @@
+// Copyright 2025 The NATS Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at:
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package io.nats.client;
+
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.function.Supplier;
+
+public class TestingDynamicTokenSupplier implements Supplier<char[]> {
+    AtomicInteger counter = new AtomicInteger(0);
+
+    @Override
+    public char[] get() {
+        return ("dynamic-token-" + counter.incrementAndGet()).toCharArray();
+    }
+}